1. Field of the Invention
The present invention relates to a consortium of nitrifying bacteria and to its use, particularly in aquaculture.
2. Description of Related Art
In aquaculture systems, the accumulation of high concentrations of ammonia and nitrite, toxic to aquatic organisms, is commonly prevented by active removal by nitrifying microorganisms including ammonia oxidizing bacteria (AOB) and nitrite oxidizing bacteria (NOB). Traditionally, the bacteria responsible for the oxidation of ammonia and nitrite in aquaria were considered to be Nitrosomonas europaea and Nitrobacter winogradskyi. In newly set-up aquaria, ammonia and nitrite can reach concentrations toxic to fish, crustaceans, and other aquatic invertebrates before a sufficient biomass of AOB and NOB become established. To reduce the length of time for establishment of NOB, commercial preparations of these organisms, are available to seed the aquarium environment, including mixed cultures of autotrophic AOB and NOB organisms.
U.S. Patent Publication No. 2004/0101944 relates to a microbiological culture and use of this culture, inter alia, for removing harmful substances, such as nitrogen compounds; the microorganisms may be selected from nitrification microorganisms, e.g., Nitrosomonas eutropha or Nitrobacter winogradskyi. 
U.S. Pat. No. 6,207,440 describes an isolated bacterial strain capable of oxidizing nitrite to nitrate and a method of use thereof for preventing or alleviating the accumulation of nitrite in an aqueous medium.
It is an object of the present invention to provide an improved consortium of nitrifying bacteria.